I agree with you 100%. Samsung xommunity appears to be populated by a lot of Samsung staff helpfully clicking "solved" for their employer!
Try using the Samsung Members app. It worked for me.
Please see my reply above. That Samsung Members solution worked for me. I hope it does for you as well
I had high hopes for this solution as I've had this issue since I updated my Note 9 to Pie as well, it's VERY annoying. Unfortunately, this didn't work for me at all.
Did you have to do anything else besides toggling the screen rotation optimization switch?
It's not giving me my auto rotate button back. I can auto rotate again after resetting my settings, and I see the auto rotate in the Samsung Members app where you said, but clicking on optimize, or turning auto rotate off and back on doesn't bring back the missing button in the pull down menu 😕
I tried the suggestion above without luck.
I only got the auto-rotate/portrait toggle back after the May security update. I hope this works for everyone else...